Combined single and double action firing mechanisms for pistols and kits for converting single-action pistols

ABSTRACT

A double-action trigger mechanism for automatic pistols in which the firing mechanism of the original single-action design of pistols, such as the Government Model 1911, is retained and continues to function in the same way as before. Conversion of existing pistols is made feasible by providing a cocking link between the trigger and the hammer which is completely separate from the single-action sear mechanism, thereby retaining the same operation in firing the gun in single-action while adding doubleaction, that is, the capability of cocking and firing the gun by means of the trigger.

United States Patent 91 Seeca'mp 1 COMBINED SINGLE AND DOUBLE ACTIONFIRING MECHANISMS FOR PISTOLS AND KITS FOR CONVERTING SINGLE-ACTIONPISTOLS [76] Inventor: Louis W. Seecamp, 561 Whitney T Avenue, NewHaven, Conn.

'22 Filed: Jan. 1 4, 1971 21 Appl. No.: 106,367

[52] US. Cl ..89/147 [51] Int. Cl. ..F4lc 19/14 [58] Field of Search..42/65, 69 B; 89/147 [56] References Cited v UNITED STATES PATENTS2,464,427 v1%)1949 Wilson ....s9/147 [451 Mar. 27, 1973 PrimaryExaminer-Stephen Bentley AttonieySteward & Steward, Merrill F. Stewardand Donald T. Steward ABSTRACT A double-action trigger mechanism forautomatic pistols in which the firing mechanism of the originalsingle-action design of pistols, such as the Government Model I911, isretained and continues to function in the same'way as before. Conversionof existing pistols is made feasible by providing a cocking link betweenthe trigger and the hammer which is completely separate from thesingle-action sear mechanism,

- thereby retaining the same operation in firing the gun insingle-action while adding double-action, that is, the capability ofcocking and firing the gun by means-of the trigger. a

5 Claims, 7 Drawing Figures ll; 80 I PATENTEDHARZY m3 SHEET 2 OF 2 FIG.4

,IOO ,94 ,96 ,20,26 ,30

FIRING MECHANISMS FOR PISTOLS AND KITS FOR CONVERTING SINGLE-ACTIONPISTOIS BACKGROUND OF THE INVENTION This invention relates to firearmsand more particularly to an improved firing mechanism forsemi-automatic, slide-action pistols of the 1911 Government type,originally manufactured by Colts Patent. Firearms Company. The basicdesign for this famous pistol is shown in the U.S. Pat. to J. M.Browning, No. 580,924 dated Apr. 20, 1897 and No. 984,519 dated Feb. 14,1911. While pistols of this design are available in various calibers,the most common and best known is usually referred to as a Colt .45, onemilitary model of which is designated M191 1A1. and is accordinglyreferred to hereinafter simply as a Colt .45 or as a Government Model191 1.

In order to fire the first round in a Colt .45, it is necessary beforepulling the trigger to cock 'the' hammer manually by means of theexposed thumbpiece on the hammer or by retracting the slide. This typeof trigger action is referred to single-action, as opposed to adouble-action, in which the gun may be cocked and fired in onecontinuous pull of the trigger. It is an object of the present inventionto provide a double-action Colt .45, which can still be fired usingsingleaction in the same manner that this wellknown weapon has beenfired for some 60 years or more. Furthermore, it is contemplated thatthe invention will usually be employed in modifying existing weaponsalready owned and used by sportsmen and gun collectors, rather than inthe manufacture of new guns.

It will be appreciated, however, that the development of an inexpensiveand reliable way of converting existing guns poses rather difficultproblems, both in design and economy, which are not involved in thedevelopment and production of a new gun. In fact, many times it is muchmore difficult to modify an existing design, while retaining itsoriginal operation and as many of its original parts as possible and atthe same time improving upon it, than it is to design an entirely newgun having the same features. Such is the case in developing a practicaldesign for converting existing Government Model 1911 pistols andthe likefor double-action. Unless 'the conversioncan be made simply andinexpensively, it would be more practical to make and sell an entirelynew gun than to convert existing ones. The present invention makes thisconversion so easy that it is possible to furnish inexpensive kits, withwhich the owner of any Colt .45 or automatic pistol of similar designcan himself convert his gun for doubleaction without altering itsoriginal single-action. to linked Handguns, including revolvers aswellas pistols, have been provided heretofore with firing mechanisms forboth single-action and double-action firing. However, such guns arebasically double-acting and become single-acting when the hammer iscocked either by pulling it back manually or automaticallyon recoil ofthe slide in the case of a slide-action pistol. For example, the pistolshown in U.S Pat. No. 3,152,418 to Charron is a double-actingarrangement with a-screw adjustment for converting to single-actionexclusively. The, firing mechanism of the Charron patent is similartothat dis closed earlier in U.S. Pat. No. 2,846,925 to Norman,

which provides a drawbar for cocking the hammer when the trigger isretracted. However, this arrangement requires the-intervention of aseparate sear that is operated by the drawbar during double-actionfiring when the trigger is retracted beyond the point required forcooking the hammer.

Another double-action firing mechanism is shown in U.S. Pat. to WaltherNos. 2,135,992 and 2,259,404,

both of which show a cocking piece which is distinctfrom the drawbar forcocking and subsequently serving as a sear. Still another such mechanismis the drawbar sear with the hammer.

Although these prior patents show double-action mechanisms capable ofsingle-actionfiring, none discloses or suggests the provision of acocking link which is completely separate from the single-action searand has no effect on it.

SUMMARY or THE INVENTION The present invention achieves the addition ofdouble-action operation to single-action pistols which have a pivotedhammer by providing a cocking link from the trigger to the hammer forengagement with a cocking lug on the hammer. In order to retain theoriginal single-action firing of the pistol the cocking link must becompletely separate from the single-action sear means, which in the caseof the Government Model 1911 includes the pivoted sear and disconnector.In addition, the'trigger must be separate from the sear-actuator so thatit can be swung through an additional amount of travel before it engagesthe sear-actuator, thereby making it possible for the trigger to cockthe hammer as it is retracted through this additional travel. Anessential aspect of the present invention resides in the provision onthe cocking link of a trigger-positioning surface which is engaged bythe hammer as it is being cocked manually or on recoil, so that thetriggeris retracted by the hammer from its extreme forward, ordouble-action position, to a single-action position intermediate suchdouble-action position and a hammer-release position adjacent itsopposite limit of travel when fully retracted. The single-actionposition of the trigger should be located such that the distance throughwhich the trigger moves upon being retracted toits hammerreleaseposition is the same as the trigger travel of the original gun, therebyretaining the same trigger action and feel of the original as if theconversion to include double-action had not been made.

DESCRIPTION OF THE PREFERRED EMBODIMENT One embodiment of the inventionis shown in the accompanying drawings, in which FIG. 1 is a fragmentaryside elevational view of the rear portion of aGovernment Model 1911modified in accordance with the present invention, portions beingremoved or broken away and shown partly in cross-section;

FIG. 2 is a fragmentary view similar to FIG. 1, but showing all theparts required for conversion to doubleaction in accordance with theinvention, with the hammer uncocked and the trigger released;

FIG. 3 is a view similar to FIG. 2, but showing the positions of theparts when the hammer is cocked on single-action;

FIG. 4 is another view similar to FIG. 2, but showing the positions ofthe parts during double-action with the hammer pivoted to a cockedposition at the moment of incipient release;

FIG. 5 is a detail view of the trigger bar taken in horizontalcross-section on the line 5-5 in FIG. 3; and

FIGS. 6 and 7 are detail views on a greatly enlarged scale showing theinteraction of the hammer cocking lug and the cocking link duringsingle-action firing and double-action firing, respectively.

As mentioned hereinbefore, the basic design and operation of the Colt.45 automatic pistol is not changed by the addition of a double-actiontrigger mechanism in accordance with the present invention. However, inorder to provide the action required for cocking the hammer 10, apivoted trigger 12 is employed in place of the sliding trigger of theoriginal gun. In addition, the trigger bar 14, which is separate fromtrigger 12, is used in place of the sear-actuator that is an integralpart of the trigger in the Colt .45. This permits the trigger to swingthrough an additional amount of travel before it engages trigger bar 16so that the trigger can cock the hammer while being retracted throughthis additional travel. A cocking lug 16 is also provided on the lowerportion of hammer for engagement by a hook 18 (FIG. 2) on the rear endof a horizontally disposed cocking link 20 pivoted at its other end toan upwardly extending cocking-portion 22 of trigger 12. The cocking link20 and cocking lug 16 are of course not parts of the original gun andmust be furnished separately, as for example in a conversion kit.

The frame 24 of the original gun may be modified to receive the pivotedtrigger l2 and cocking link 20 by machining a horizontally elongatedrecess 26, best shown in FIG. 2, in its right-hand side 28, in order toprovide space within which to receive cocking link 20. In addition,access space is provided above the trigger for its cocking-portion 22,and an opening 29 is cut laterally therefrom into recess 26, throughwhich a pivot pin 30 on cocking link 20 extends into pivotal engagementwith the trigger. An arcuately shaped access opening 31 is also cut fromthe rear portion of recess 26, so that cocking-lug 16 may extendlaterally into recess 26 from hammer 10 for engagement by the hooked end18 of cocking link 20. Since a longer trigger travel is required forcocking the hammer by means of a double-action trigger than is requiredwhere a single-action trigger is employed, the original trigger guardmust be replaced by one that will accommodate the double-action trigger.

The trigger 12 is mounted on a pivot pin 32 in the substitute triggerguard 34, which is provided on a lower rear portion with a tongue 36(FIG. 1) that fits snugly within a groove machined in the mating surfaceof the handle portion 37 of frame 24, from which the original triggerguard was removed. The upper portion of the new trigger guard 34 may beprovided with horizontally extending dovetail surfaces which fit withina mating dovetail groove, indicated generally at 38 (FIG. 1), cut in theunder surface of the upper portion of frame 24, from which the originaltrigger guard was also removed. The trigger guard 34 may then bepermanently staked in place, as for example, by a pin 40.

Under present-day circumstances, it is more desirable to provide a newframe 24, including the modified trigger guard 34 and cockinglink-receiving recess 26 as part of the conversion kit, therebyeliminating the necessity of machining the old frame. This alternativeis entirely practical, not only because in many cases replacement of theframe is needed in guns which have seen hard service in the military andelsewhere, but also because all of the parts of the original gun exceptfor the frame, hammer and trigger may be re-assembled in the replacementframe. Accordingly, the cost of modifying the original frame underpresent conditions in the United States at least, is actually greaterthan the cost of a new frame. Despite this, the conversion todoubleaction, including the new frame, can still be done by the owner ofthe original pistol for only about half the cost of a new Colt .45.Moreover, a new Colt automatic that has not been modified would ofcourse have the disadvantage of the usual single-action trigger only.

Referring now in greater detail to the drawings, it will be seen how thedouble-action trigger mechanism is incorporated while still retainingthe single-action and feel of the original gun. Thus, except for theaddition of the cocking lug 16, the hammer 10 is identical with that ofthe original and is pivoted on a hammer pin 40. The usual sear notch 42is also provided in the underside of the hammer. The scar 44 ispivotally mounted on a sear pin 46 for movement of its sear nose intoand out of engagement with sear notch 42. The disconnector 48 extendsvertically along both sides of sear 44 for engagement at its upper endby the underside of the slide 50 and at its lower end 52 by the triggerbar 14. Disconnector 48 has an enlarged opening 54, through which searpin 46 extends thereby permitting limited vertical and lateral movementof the disconnector with respect to sear 44. The upper end of aleaf-spring 56 engages the inclined surface on the back of the lower end52 of disconnector 48, urging it forward against the cross piece 57 oftrigger bar 14. Leaf-spring 56 also urges disconnector 48 upward so thatits upper end projects into a recess 58 in the under surface of slide50. When disconnector 48 is at its upper limit of travel as shownin'FIGS. 1 and 2, its lower end 52 is disposed between the lower end ofsear 44 and trigger bar 14 so that when the trigger 12 is fullyretracted to its hammer-release position, the sear 44 is pivotedclockwise in order to disengage the nose of the sear from the sear notch42 of the cocked hammer.

However, when the slide 50 is retracted either manually or on recoil,the recess 58 is moved out of alignment with the upper end ofdisconnector 48 so that the disconnector is moved down by the undersideof slide 50. This moves the lower end 52 of disconnector 48 to aposition where it no longer operatively engages sear 44, therebydisconnecting trigger bar 14 from the sear. Then, regardless of whethertrigger bar 14 is retracted or not, sear 44 is free to be pivoted in acounterclockwise direction (as viewed in FIG. 1 by the sear spring 60into its hammer-cocking position. If the trigger is held back after ashot is fired, the disconnector 48 becomes blocked by the lower end ofsear 44 against movement upward again into recess 58 upon return ofslide 50 to battery position, thereby disconnecting the sear from thetrigger bar. Consequently, it is necessary to release the trigger 12after each shot in order to re-connect the sear with the trigger barthrough disconnector 48 for the next. shot, thus preventing the firingof more than one shot for each pull of the trigger.

Hammer may be pivoted into a cocked position by its exposed thumb-pieceor by retraction of slide 50 manually, or on recoil, the hammer spring62. being compressed on cocking so that the hammer will fall on beingreleased from its cocked position to strike the firing pin 64 in slide50 in order to fire a cartridge in the chamber of barrel 66. Recoil onfiring drives the slide rearward, ejecting the empty case, recockinghammer l0, and reloading the chamber with a fresh cartridge from themagazine (not shown) in the handle portion 37 of the frame 24, all inprecisely the same way that the original pistol functions.

The Colt .45 also has a safety device in the handle which must bedepressed in order to release sear 44 from cocking engagement withhammer 10. The grip safety comprises a pivoted safety member 70 in theupper back portion of the handle 37 below hammer 10. As best seen inFIGS. 3 and 4, safety member 70 is pivoted on a pin 72 and has a finger74 which projects forward into abutting relation with trigger bar 14 toone side of disconnector 48, thereby preventing actuation of the triggerbar. The action of a leaf-spring 75 resiliently holds safety 70 in thesafe position. If the pistol is held the proper way. in one hand, safetymember 70 is pivoted forward (counterclockwise as viewed in thedrawings) as the hand of the shooter grips the handle 37. Such forwardmovement of safety member 70 lifts the end of itsfinger 74 out ofabutting relation with trigger bar 14, so that the latter can beretracted far enough to pivot the sear 44 out of cocking engagement withthe hammer. It will be noted that the sear 44, disconnector 48, searspring 60, disconnector spring 56, hammer spring 62 and grip safety 70,as well as all other parts of the gun including those not shown, areidentical with and interchangeable with, the corresponding parts of theoriginal pistol and, therefore, do not need to be furnished with thedouble-action conversion kit of the present invention. In fact, exceptfor the frame that can be either modified or replaced, the only parts ofthe original gun which are not used are the hammer and trigger.

The pivoted trigger 12 is urged in a counterclockwise direction asviewed in FIG. 1, by a trigger spring 76, one end of which seats in arecess in the upper part of the trigger and presses downward to pivotthe trigger while the other end of spring 76 engages a fixed portion ofthe frame 24 within the access space provided for the trigger. The rearside of the finger portion 80 of the trigger is desirably rounded andconvex in shape for engagement with a downwardly disposed abutment 82 atthe front end of the trigger bar 14. An adjusting screw 84 (FIG. I) maybe provided in the depending portion of abutment 82 for adjusting theamount of movement or over-travel of trigger 12 following release of thehammer by sear 44 when the pistol is fired by single-action triggeractuation.

Referring more particularly to FIG. 5, trigger bar 14 is a rectangularmember which is identical in shape to the corresponding portion of theoriginal trigger except that it is separate from the trigger and has thedowntumed abutment 82 for engagement by the trigger. The longitudinalside portions 86, 86 of trigger bar 14 are guided in grooves 87, 87 oneach'side of the handle portion 37 of the frame, so that the cartridgemagazine (not shown)-can be inserted between them. The cross piece 57 atthe rear of trigger bar 14 joins the two longitudinal side portions 86,86 and is engaged by the front side of the lower end 52 of disconnector48, which in turn is continuously pressed forward against trigger bar 14by the leaf-spring 56. The forward travel of trigger bar 14 is limitedby engagement of its shoulders 88 on opposite sides of abuttment 82 withcorresponding stop surfaces 89, 89 on trigger guard 34, through anopening 90 in which abutment 82 projects for engagement by trigger 12.

It will be apparent therefore that when hammer 10 is cocked as shown inFIG. 3 and the trigger pulled to fire the gun, the rear surface oftrigger 12 engages abutment .82 on trigger bar 14 forcing it rearwardlyagainst the action of spring 56. Such rearward travel of trigger bar 14to its hammer-release position, which is identical withthe action of thetriggerof a Colt .45, pivots sear 44 out of the cocking notch 42 ofhammer 10 for 7 2 and 3) in the lower side of the recess 26 of frame 24.

Cocking link 20 has room within recess 26 for limited movement bothhorizontally and vertically. When the hammer is uncocked and the triggerreleased as shown in FIG. 2, the hook 18 on cocking link 20 is movedupward by the action of spring 91 into operative engagement with thecocking lug 16 of hammer 10, thereby limiting pivotal movement of link20 in this direction. Pivotal movement of cocking link 20 about pivotpin 30 in a clockwise direction is also limited by engagement of apivot-hump 94 on the top edge of cocking link 20 with the upperside ortrack 96 of recess 26. It will be noted that when the hammer and triggerare in the positions shown in FIG. 2, the hump 94 is in engagement withtrack 96, but that when the cocking link 20 is returned to this positionfollowing firing of the last round, its hook-end 18 can. move down as itengages the front, lower side of cocking lug 16.

As trigger 12 is retracted from its normal position for double-actionshown in FIGS. 1 and 2, the forward end of cocking link 20 is liftedupward and forward, causing the cocking link to rotate about itspivot-hump 94 at the same time that it is advanced forward. Thus, whenthe pistol is fired in double-action, the cocking hook l8 draws the lug16 on hammer 10 to the position shown in FIG. 4 for cocking the hammer.At the same time, due to its rotational movement about hump 94, the

hook-end of cocking link 20 is forced downward, withdrawing hook 18 fromengagement with cocking lug 16. In the meantime, pivotal movement ofhammer 10, as it is being cocked, causes cocking lug 16 to move upwardlyuntil only the tip of cocking hook 18 and rear end-portion of cockinglug 16 remain engaged with each other at the point of insipient releaseof hammer 10.

The double-action of trigger 12 is clearly illustrated in FIG. 7, whichis a greatly enlarged diagrammatic view of the rear portion of cockinglink 20, cocking lug 16 and pivot pin 40 for hammer 10, together with aportion of the upperside of recess 26 that forms the track 96, alongwhich the hump 94 of cocking link 20 slides as the hammer is beingcocked. The full-line positions of cocking link 20 and cocking lug 16shown in FIG. 7 are the same as in FIG. 4, with cocking lug 16 just onthe point of being released by the cocking hook 18. It should be notedhow downward movement of hook 18 from its initial position (broken-lineshowing) of full engagement with lug 16 and simultaneous upward movementof lug 16 as the hammer is cocked combine to provide a smooth, positivecocking and releasing action of trigger 12. During the very lastincrement of the trigger travel, which occurs suddenly and almostinstantaneously with the release of cocking lug 16 by hook 18, cockinglink 20 moves slightly forward of its full-line position shown in FIG. 7and is permitted to pivot downward slightly when the rounded tip of itshook 18 is engaged by the underside 98 of cocking lug 16 as the hammerfalls under the action of hammer spring 62.

If a cartridge is in the chamber of barrel 66 and the magazine is notempty, the recoil on firing the cartridge in the chamber extracts andejects the empty case, recocks hammer and chambers a fresh cartridge.During this automatic reloading cycle, cocking lug 16 moves forward ashammer 10 is cocked on being pivoted back by the recoiling slide 50,this time slightly beyond its full-line position shown in FIGS. 4 and 7,where it is held upon engagement of sear 44 in sear notch 42 of thehammer, as shown in FIG. 3.

When the trigger is used in double-action both to cock and release thehammer, it is pivoted into engagement with the abutment 82 on triggerbar 14, so that during the balance of the travel of trigger 12, triggerbar 14 is also actuated, as if to release the hammer from the positionin which it is located when cocked by sear 44. This position is hereinreferred to as the searcocked position in order to differentiate fromthe position referred to as the cocked position, to which the hammer ismomentarily cocked during double-action trigger actuation. It will beappreciated, however, that depending on how the parts are designed, thesearcocked position on single-action and the cocked position ondouble-action may coincide.

In the construction shown for illustrative purposes in the drawings, thesear 44 is moved by trigger bar 14 out of engagement with hammer 10during double-action substantially simultaneously with the release ofcocking lug 16 by the hook 18 on cooking link 20. However, thissituation is not critical, because even if the sear is not actuated bytrigger bar 14 until after the hammer has been released by cocking bar20 during double-action firing, the force on the trigger 12 required forcocking the hammer is necessarily great enough to ensure immediate, ifnot instantaneous retraction of the trigger through its final, short,sear-actuating movement as soon as the hammer escapes cocking hook 18.Similarly, the present arrangement permits release of the hammer bycocking hook 18 on double-action slightly before the hammer is pivotedfar enough for the nose of sear 44 to engage in sear notch 42. But hereagain such a situation is not critical for the reasons here indicated.It will be apparent therefore that no great care is required to ensurepositive release of hammer 10 from its cocked position on conversion ofthe pistol to a double-action trigger in accordance with the presentinvention. Consequently the cocked position of the hammer when fired indouble-action may be said to coincide only approximately with itssear-cocked position.

Cocking link 20 is provided on its upper edge between hook 18 andpivot-hump 94 with a triggerpositioning projection 100, which has a flatsurface 102 (FIGS. 6 and 7) disposed at a predetermined distance fromthe pivot pin 30, by which link 20 is connected to trigger 12. Onrelease of the trigger after the gun has been fired and automaticallyreloaded and cocked, the trigger 12 does not return to its forward-mostor double-action position of FIGS. 1 and 2, but remains instead inengagement with abutment 82 on trigger bar 14 at what is referred tohereinafter as its single-action position, which is shown in FIG. 3.This is due to the fact that the hammer is cocked immediately uponrecoil of the slide 50, thereby positioning cocking lug 16 in the pathof projection on cocking link 20 so that on release of the trigger thecocking link moves rearward under the action of trigger spring 76 but isblocked from returning to its initial position shown in FIG. 2(full-line position in FIG. 6). Such blocking of the cocking link iscaused by engagement of the surface 102 on projection 100 with cockinglug 16, as illustrated in FIG. 3 and in broken-lines in FIG. 6. Thisshort return-movement of cocking link 20 permits trigger 12 to pivot farenough forward for trigger bar 14 to move to a point at which thedisconnector 48 is allowed to move upward into operativerelation withsear 44 for actuating the sear on the next pull of trigger 12. Trigger12, however, remains engaged with the trigger bar 14.

By properly selecting the distance between the positioning surface 102and the pivot pin 30, as well as the length of trigger bar 14, thetrigger 12 can be located in exactly the same position for single-actionas the trigger in the original pistol when it is at ready position inits forwardmost limit of travel. Consequently, on firing the modifiedgun of the present invention after the hammer has been cocked, theaction of the firing mechanism is the same as that of the original andthe trigger travel is the same. The only difference in the triggeraction is in the pivotal movement of the modified trigger as comparedwith the straight, sliding action of the trigger in the original. Thisdifference is so slight that it is scarcely noticeable.

, In order to retain the original trigger travel on firingsingle-action, it is necessary that the positioning surface 102 oncooking link 20 be reasonably accurately disposed relative to cockinglug 16 and that the position of abutment 82 on trigger bar 14 bedetermined to ensure proper engagement of trigger 12 with trigger bar 14when positioning surface 102 engages cocking lug 16. This relationshipmust be established both to ensure that there is no gap between thetrigger and the trigger bar when the trigger is in its -single-actionposition and alsoto avoid disturbing the operation of the sear, as forexample, if trigger 12 were prevented from returning far enough torelease the disconnector. in order to better determine thisrelationship, a flat surface 104 is formed adjacent the forward end 106FIG. 6) Of cocking lug 16 at an angle with its under surface 98, suchthat when the lug 1 6 and cocking link 20 are in the positions shown inbroken-lines'in-FIG. 6, their respective surfaces 104'and 102 meet infullengagement with each other.

When the hammer is uncooked and it is desired to fire the gun in theconventional manner by first cocking the hammer manually-that is, byretracting the thumb-piece on the hammer or, in order to chamber acartridgefollowing reloading with a fresh magazine, by retracting theslide 50 by hand -the act of first manually cocking the harrimer resultsin movingthe trigger from its double-action position to itssingle-action position. The pistol can' then be fired in single-actionby pulling the'trigger through the balance of its travel. When thehammer is cocked manually, movement of the trigger from itsdouble-action position to its single-action position is effected byengagement of cocking lug l'6with an upwardlyinclined surface 108 on therear side of positioningprojection 100. This action is apparent'fromFIG. 6, in which the lug l6 and cocking link 20 are shown in full lineswhen the hammer is uncooked and the trigger isin its double-actionposition as in FIG. 2 Thus, cocking lug l6 isswung from the positionshownin full lines to the position shown in broken lines where hammer 10becomes cocked by engagementof sear 44 insear notch 42, (FIG; 3). Duringthe course of this movement, the tip 106 of lug 16 engages the inclinedsurface 108 on cocking link 20, moving'it to the right as viewed in thedrawings until the positioning surfaces 102 and 104 on the cocking linkand lug 16, respectively, engage as illustrated in broken lines in FIG.6. Movement of cocking link 20 to' this position pivots the fingerportion 80 of trigger 12 into engagement with trigger bar 14 withoutdisengaging sear 44 from the hammer. The gun is then in the samecondition-which it assumes following automatic reloading under recoil.

What is claimed is:

1. In a semi-automatic pistol, a firing mechanism for firing the pistolin both single and double action comprising in combination a pivotedhammer having provision for being manually cooked and for movementbetween a cocked position and a fired position,

a trigger pivotally mounted for movement about a fixed pivot,

single-action sear means for releasably retaining said hammer in asear-cocked position including a scar movably mounted for cockedengagement with said hammer upon pivotal movement of said hammer into asear-cocked position, and also including a sear-actuator separate fromsaid trigger but mounted for engagement thereby,

said trigger having limited travel between a doubleaction positionadjacent one of its extremities of travel, a hammer-release positionadjacent its other and an intermediate single-action position at whichit engages said sear-actuator and is poised for release of said searfrom cocking engagement with said hammer, said trigger having a fingerportion and a cocking portion disposed on the opposite side of its pivotfrom said finger portion,

a cocking link pivotally connected to said cocking portion of saidtrigger for movement completely separate from said sear for pivotingsaid hammer to a cocked position approximately coinciding with its saidsear-cocked position upon retraction of said trigger from itsdouble-actionposition,

a cocking lug rigidly mounted on and forming part of said hammer foroperative engagement by said cocking link,

said cocking link having a cocking surface disposed for engagement withsaid cocking lug when said hammer is uncooked for pivoting said hammertoward its cocked position upon movement of said cocking link in onedirection during such retraction of said trigger and for releasing saidhammer when it reaches said cocked position,

said cocking link also having a trigger-positioning surface forengagement by said hammer as it is cocked other than by means of saidtrigger in order to move said cocking link in said one direction and tolocate said trigger in its said single-action position.

2. A firing mechanism as defined in claim 1, wherein said sear-actuatorcomprises a trigger bar separate from saidtrigger and mounted forlimited movement sufficient to pivot said sear out of cocking engagementwith said hammer, said trigger being out of engagement with said triggerbar when in its said double-action position and being retractible intoengagement with said trigger bar when in its said single-actionposition, spring means for resiliently moving said trigger towards saiddouble-action position, said trigger-positioning surface on said cockinglink being engageable by said cocking lug on said hammer for moving saidcocking link against the action of said spring means as said trigger ismoved by said cocking link into its single-action position.

3. A firing mechanism as defined in claim 2, wherein said cocking linkis also mounted for pivotal movement about said cocking portion of saidtrigger and said cocking surface on said cocking link is disposed on ahook portion of said cocking link for operative engagement with saidcocking lug on said hammer on pivotal movement of said cocking link inone direction of rotation, a cocking-link spring urging said cockinglink in said one direction of rotation, and means for limiting themovement of said cocking link in said one direction of rotation in orderto effect release of said cocking lug when said hammer is pivoted to itscocked position by retraction of said trigger.

4. A firing mechanism defined in claim 2, wherein said sear is moved outof cocking engagement with said hammer substantially simultaneously withrelease of said cocking lug by said cocking link during double-actionactuation of said firing mechanism.

5. A double-action conversion kit for a semi-automatic pistol having afiring mechanism originally designed with a single-action trigger onlyand having a frame for mounting a pivoted hammer, single-action searmeans including a sear normally urged into cocked engagement with thehammer and a sear actuator on the trigger for releasing said sear, theframe having guide means on which the sear actuator is supported, saidkit comprising a replacement trigger having 3. depending finger portion,a hammer-cocking portion and means located between said portions forpivotal mounting in the pistol,

a replacement hammer identical in all respects to the original hammerbut having a cocking lug rigidly mounted thereon,

a replacement frame formed in all respects identical to the originalframe for holding and assembling all the original parts of the pistolexpect the hammer and trigger, but having means for pivotally mountingsaid replacement trigger and an elongated recess in one side between thetrigger and hammer including access thereto, said replacement framehaving a guide-way for a scar actuator similar to the guide means in theoriginal frame,

said replacement trigger being pivotally movable on said replacementframe between a double-action position at one of its limits of travel, ahammerrelease position at its other and an intermediate single-actionposition at which it is poised for release of said sear,

a trigger spring fitting within a portion of said recess in saidreplacement frame adjacent said trigger for continuously urging saidtrigger toward its doubleaction position,

a trigger bar similar to the sear actuator of the original pistol butseparate from said replacement trigger and movable within said guide-wayin said replacement frame between said replacement trigger and saidsear, said trigger bar being adapted for engagement by said replacementtrigger when the latter is in its single-action position such that uponretraction of said replacement trigger from said single-action positionto its sear-release position said sear is disengaged from said hammer,said trigger being movable independently of said trigger bar between itsdouble-action and singleaction positions,

a cocking link pivotally connected to said cocking portion of saidreplacement trigger for both pivotal and longitudinal movement withinsaid recess in said replacement frame, said cocking link beingcompletely separate from said single-action sear and having a cockingsurface disposed for engagement with said cocking lug on saidreplacement hammer when said hammer is uncocked and for pivoting saidhammer toward its cocked position upon movement of said cocking link inone direction during retraction of said trigger from its double-actionposition and for releasing said hammer when it reaches said cockedposition,

said cocking link also having a trigger-positioning surface forengagement by said replacement hammer as it is cocked other than bymeans of said re ilacement trigger in order to move said cocking lm insaid one direction and to locate sai replacement trigger in its saidsingle-action position.

1. In a semi-automatic pistol, a firing mechanism for firing the pistolin both single and double action comprising in combination a pivotedhammer having provision for being manually cocked and for movementbetween a cocked position and a fired position, a trigger pivotallymounted for movement about a fixed pivot, single-action sear means forreleasably retaining said hammer in a sear-cocked position including asear movably mounted for cocked engagement with said hammer upon pivotalmovement of said hammer into a sear-cocked position, and also includinga sear-actuator separate from said trigger but mounted for engagementthereby, said trigger having limited travel between a double-actionposition adjacent one of its extremities of travel, a hammerreleaseposition adjacent its other and an intermediate singleaction position atwhich it engages said sear-actuator and is poised for release of saidsear from cocking engagement with said hammer, said trigger having afinger portion and a cocking portion disposed on the opposite side ofits pivot from said finger portion, a cocking link pivotally connectedto said cocking portion of said trigger for movement completely separatefrom said sear for pivoting said hammer to a cocked positiOnapproximately coinciding with its said sear-cocked position uponretraction of said trigger from its double-action position, a cockinglug rigidly mounted on and forming part of said hammer for operativeengagement by said cocking link, said cocking link having a cockingsurface disposed for engagement with said cocking lug when said hammeris uncocked for pivoting said hammer toward its cocked position uponmovement of said cocking link in one direction during such retraction ofsaid trigger and for releasing said hammer when it reaches said cockedposition, said cocking link also having a trigger-positioning surfacefor engagement by said hammer as it is cocked other than by means ofsaid trigger in order to move said cocking link in said one directionand to locate said trigger in its said single-action position.
 2. Afiring mechanism as defined in claim 1, wherein said sear-actuatorcomprises a trigger bar separate from said trigger and mounted forlimited movement sufficient to pivot said sear out of cocking engagementwith said hammer, said trigger being out of engagement with said triggerbar when in its said double-action position and being retractible intoengagement with said trigger bar when in its said single-actionposition, spring means for resiliently moving said trigger towards saiddouble-action position, said trigger-positioning surface on said cockinglink being engageable by said cocking lug on said hammer for moving saidcocking link against the action of said spring means as said trigger ismoved by said cocking link into its single-action position.
 3. A firingmechanism as defined in claim 2, wherein said cocking link is alsomounted for pivotal movement about said cocking portion of said triggerand said cocking surface on said cocking link is disposed on a hookportion of said cocking link for operative engagement with said cockinglug on said hammer on pivotal movement of said cocking link in onedirection of rotation, a cocking-link spring urging said cocking link insaid one direction of rotation, and means for limiting the movement ofsaid cocking link in said one direction of rotation in order to effectrelease of said cocking lug when said hammer is pivoted to its cockedposition by retraction of said trigger.
 4. A firing mechanism defined inclaim 2, wherein said sear is moved out of cocking engagement with saidhammer substantially simultaneously with release of said cocking lug bysaid cocking link during double-action actuation of said firingmechanism.
 5. A double-action conversion kit for a semi-automatic pistolhaving a firing mechanism originally designed with a single-actiontrigger only and having a frame for mounting a pivoted hammer,single-action sear means including a sear normally urged into cockedengagement with the hammer and a sear actuator on the trigger forreleasing said sear, the frame having guide means on which the searactuator is supported, said kit comprising a replacement trigger havinga depending finger portion, a hammer-cocking portion and means locatedbetween said portions for pivotal mounting in the pistol, a replacementhammer identical in all respects to the original hammer but having acocking lug rigidly mounted thereon, a replacement frame formed in allrespects identical to the original frame for holding and assembling allthe original parts of the pistol expect the hammer and trigger, buthaving means for pivotally mounting said replacement trigger and anelongated recess in one side between the trigger and hammer includingaccess thereto, said replacement frame having a guide-way for a searactuator similar to the guide means in the original frame, saidreplacement trigger being pivotally movable on said replacement framebetween a double-action position at one of its limits of travel, ahammer-release position at its other and an intermediate single-actionposition at which it is poised for release of said sear, a triggerspring fitting witHin a portion of said recess in said replacement frameadjacent said trigger for continuously urging said trigger toward itsdouble-action position, a trigger bar similar to the sear actuator ofthe original pistol but separate from said replacement trigger andmovable within said guide-way in said replacement frame between saidreplacement trigger and said sear, said trigger bar being adapted forengagement by said replacement trigger when the latter is in itssingle-action position such that upon retraction of said replacementtrigger from said single-action position to its sear-release positionsaid sear is disengaged from said hammer, said trigger being movableindependently of said trigger bar between its double-action andsingle-action positions, a cocking link pivotally connected to saidcocking portion of said replacement trigger for both pivotal andlongitudinal movement within said recess in said replacement frame, saidcocking link being completely separate from said single-action sear andhaving a cocking surface disposed for engagement with said cocking lugon said replacement hammer when said hammer is uncocked and for pivotingsaid hammer toward its cocked position upon movement of said cockinglink in one direction during retraction of said trigger from itsdouble-action position and for releasing said hammer when it reachessaid cocked position, said cocking link also having atrigger-positioning surface for engagement by said replacement hammer asit is cocked other than by means of said replacement trigger in order tomove said cocking link in said one direction and to locate saidreplacement trigger in its said single-action position.